Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
  • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
  • H01B1/08—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances oxides
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G55/00—Compounds of ruthenium, rhodium, palladium, osmium, iridium, or platinum
  • C01G55/002—Compounds containing ruthenium, rhodium, palladium, osmium, iridium or platinum, with or without oxygen or hydrogen, and containing two or more other elements
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
  • H01C17/06—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base
  • H01C17/065—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base by thick film techniques, e.g. serigraphy
  • H01C17/06506—Precursor compositions therefor, e.g. pastes, inks, glass frits or green body
  • H01C17/06513—Precursor compositions therefor, e.g. pastes, inks, glass frits or green body characterised by the resistive component
  • H01C17/06533—Precursor compositions therefor, e.g. pastes, inks, glass frits or green body characterised by the resistive component composed of oxides
  • H01C17/0654—Oxides of the platinum group
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
  • H01C17/06—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base
  • H01C17/065—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base by thick film techniques, e.g. serigraphy
  • H01C17/06506—Precursor compositions therefor, e.g. pastes, inks, glass frits or green body
  • H01C17/06573—Precursor compositions therefor, e.g. pastes, inks, glass frits or green body characterised by the permanent binder
  • H01C17/0658—Precursor compositions therefor, e.g. pastes, inks, glass frits or green body characterised by the permanent binder composed of inorganic material
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2002/00—Crystal-structural characteristics
  • C01P2002/30—Three-dimensional structures
  • C01P2002/36—Three-dimensional structures pyrochlore-type (A2B2O7)
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2002/00—Crystal-structural characteristics
  • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
  • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2002/00—Crystal-structural characteristics
  • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
  • C01P2002/74—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by peak-intensities or a ratio thereof only

Definitions

• the invention relates to electrically conductive pyrochlore-related oxides based on copper and / or silver, lead, bismuth and ruthenium and resistance compounds which contain these oxides.
• German patent 1 816 105 describes the electrically conductive, stable bismuth ruthenate Bi2Ru2O7 with pyrochlore crystal structure and similar oxides of the pyrochlore or distorted pyrochlore type, which contain bismuth and ruthenium and other metals. Together with a glass, they are used to make electrical resistors.
• the specific resistance of the resistors obtained with Bi2Ru2O7 can be varied over a considerable range while maintaining a low temperature coefficient in the range from + 25 ° C to + 125 ° C.
• the oxides are produced by heating the required oxides or the easily oxidizable metals or salts together under oxidizing conditions at about 600-1200 ° C. In an amount of 5 - 90%, together with a glass frit or another suitable inorganic binder, they form the solid portion of the resistance masses, which - to be printable - also contain a liquid organic carrier, for example from a solution of ethyl cellulose in terpineol.
• a liquid organic carrier for example from a solution of ethyl cellulose in terpineol.
• the preparation can be carried out by annealing the mixture of bismuth oxide carbonate Bi2O2CO3, the dioxide of ruthenium and / or iridium and the carbonates of the other metals in an oxidizing atmosphere and cleaning the reaction product with dilute aqueous mineral acid.
• It is the object of the invention to find electrically conductive ruthenates with a pyrochlore structure of the type characterized in the introduction, which are suitable for the production of thick-film resistance elements, the difference between the temperature coefficient of resistance in the range from + 25 ° C. to + 125 ° C and the temperature coefficient of resistance in the range of -55 ° C to + 25 ° C ( "C old T emperature C oefficient of R esistance" CTCR), ⁇ TCR HTCR - CTCR, should be as small as possible.
• the oxides in which the stoichiometric ratio of lead to bismuth is greater than 1 and less than 2 have proven particularly useful.
• oxides which contain lead and bismuth in a stoichiometric ratio of 1.5: 1 and copper or silver are preferred.
• the oxides can be prepared by solid-state reaction or by reaction in the liquid phase. It has proven particularly useful to use the corresponding metals, metal oxides, metal carbonates or mixtures thereof in powder form as starting materials and to anneal them in air at about 700-1000 ° C.
• the oxides together with dielectric inorganic binders, the oxides form the solid component of resistance masses.
• Solids content from 5 - 90% by weight oxides and from 10 - 95% by weight dielectric inorganic binders. All binders known for this purpose, which mostly represent glass frits, are suitable for common use with the oxides according to the invention.
• the resistance materials usually also contain an organic medium as a liquid carrier and are then present as pastes, which can be applied to the dielectric substrates, for example using the screen printing method.
• the liquid carrier usually consists of a solution of an organic polymer, for example of acrylic resin or ethyl cellulose, in an organic solvent, for example terpineol or butyl carbitol (butyl diglycol acetate), as is usually used for resistance pastes.
• the resistance pastes are produced in a known manner by mixing the constituent parts. After the pastes have been printed on substrates made of, for example, aluminum oxide and the pastes have been dried by evaporating the solvent, the printed substrates are baked in air at about 700-900 ° C. At these stoving temperatures, the oxides do not decompose, as the X-ray diffractograms of the stoved resistance layers show.
• the resistance layers produced from the resistance compositions containing oxides according to the invention are distinguished by small ⁇ TCR values and also by small HTCR and CTCR values.
• the layer thickness d [ ⁇ m] the sheet resistance R f [k ⁇ / ⁇ ]
• the Temperature coefficient of resistance in the range from -55 ° C to + 25 ° C, CTCR [ppm / K] which determines the resistance layers obtained by baking the pastes on alumina substrates.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Inorganic Chemistry (AREA)
• Organic Chemistry (AREA)
• Non-Adjustable Resistors (AREA)
• Conductive Materials (AREA)
• Inorganic Compounds Of Heavy Metals (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Electron Tubes For Measurement (AREA)

Applications Claiming Priority (2)

Publications (3)

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ID=6380157

Family Applications (1)

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• 1989
  • 1989-05-05 DE DE3914844A patent/DE3914844A1/de active Granted
  • 1989-12-20 DE DE89123515T patent/DE58907304D1/de not_active Expired - Fee Related
  • 1989-12-20 EP EP89123515A patent/EP0395799B1/de not_active Expired - Lifetime
• 1990
  • 1990-04-06 US US07/505,758 patent/US5069824A/en not_active Expired - Lifetime
  • 1990-05-07 JP JP2115950A patent/JPH0742120B2/ja not_active Expired - Fee Related

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